The key problem for preventing the onset of the age-dependent neurological diseases (Alzheimer's, Parkinson's, and ALS) lies in knowing what factor(s) triggers the cascade of events leading to neuron cell death. Similarly, halting such cascades before they have done irreparable harm to the nervous system requires knowing the stages in the cascade in the correct temporal sequence. Without addressing, and solving, these problems, only palliative efforts are possible. A number of features of each of these diseases, and a consideration of the unusual features of an unusual variant, ALS-parkisonism dementia complex (ALS-PDC), has provides some clues to etiological factors that might be crucial. Epidemiological evidence from ALS-PDC suggests an environmental dietary neurotoxin as a early trigger for neurodegeneration. A murine model of ALS-PDC based on these findings has succeeded in duplicating all of the essential features behavioral and pathological features of the human disease and provided insight into many stages in the neurodegenerative cascade. The insights gained from this model system will allow us to understand the sequence of events leading initiation to disease end state, thereby providing a basis for future treatment strategies.